The ballet of the good city sidewalk never repeats itself from place to place, and in any one place is always replete with new improvisations.

Nothing is so clear in history that is it happens for any one thing. It seems that a lot of things come together to make great changes.

observation of realities has never, to put it mildly, been one of the strengths of economic development theory.

A border--the perimeter of a single massive or stretched-out use of territory--forms the edge of an area of 'ordinary' city. Often borders are thought of as passive objects, or matter-of-factly just as edges. However, a border exerts an active influence.

I have been dwelling upon downtowns. This is not because mixtures of primary uses are unneeded elsewhere in cities. On the contrary they are needed, and the success of mixtures downtown (on in the most intensive portions of cities, whatever they are called) is related to the mixture possible in other part of cities.

The second mode to deal with unsafe cities is to take refuge in vehicles. This is the technique practiced in the big wild-animal reservations of Africa, where tourists are warned to leave their cars under no circumstances until they reach a lodge. It is also the technique practiced in Los Angeles.

New ideas often need old buildings.